Concern about cod liver oil

People's Pharmacy

Q. My aunt heard that cod liver oil is good for arthritis and has started taking it twice a day to ease her aches and pains. I worry about this since she doesn't always use common sense. Is there any danger?

A. A recent study from Sweden shows this could be a problem. Researchers found that women who got too much vitamin A in their diets had weaker bones and were more susceptible to hip fracture. A major source of vitamin A in Scandinavian countries is cod liver oil.

Norway and Sweden have some of the highest rates of hip fracture in the world. While vitamins A and D are both crucial for healthy bones, excess vitamin A is detrimental.

Q. You have written that "calcium and other minerals found in common antacids can interfere with the absorption of Synthroid." We believe this to be incorrect. Aluminum hydroxide, Carafate and ferrous sulfate are known to interfere with Synthroid absorption, but we have found no such reference to calcium.

Some of the patients in our endocrinology practice have asked if they should stop their calcium supplements. We can only imagine how many others may have done so without asking their doctors.

Please retract this statement or substantiate the interaction.

A. Please refer to the Journal of the American Medical Association (March 11, 1998, p. 750) for a description of three cases in which calcium interfered with levothyroxine absorption. We have also heard from readers who did not have the expected benefit from their thyroid (Synthroid, Levothroid, Levoxyl) when they took it with vitamins containing calcium or iron or with calcium-fortified orange juice. They experienced symptoms of low thyroid activity such as fatigue, constipation, dry skin and hair loss. People should not stop calcium, but they should leave at least four hours between thyroid and their supplements.

Write to the Graedons in care of The Sun, 501 N. Calvert St., Baltimore, Md. 21278, or e-mail to pharmacindspring.com.